Hi! Sorry to take so long to reply. I'm kinda new here and only just now realized there is a little message box in the corner of the screen. Duh.
Anyway, glad you like my layout. I used scraps of Masonite paneling turned upside down (non-grooved side up) about 1/8" or 3/16" thick. Once I got the parts cut out and fitted together I rounded over the top edges using a hand sander.